Thursday, September 27, 2012

Finland was
part of the Russian Empire in the period 1809-1917. In December 1917 the
Finnish declaration of independence led to a civil war between the Reds (supported
by the Russian Soviet Republic) and the Whites (supported by Germany). In 1918
the anti communist forces won and Finland became an independent country.

From then on the
Finns had to defend their freedom from the newly established Soviet Union. The
need to keep an eye on their powerful neighbor forced them to show special
interest in radio interception and cryptanalysis.

Tuesday, September 25, 2012

The Allied
invasion of Western Europe in WWII was codenamed ‘Overlord’. The Germans
learned of this through their spy in the British embassy in Ankara,
Turkey. This spy was controlled by the Sicherheitsdienst’s foreign intelligence
department.

General
Schellenberg, head of this department, describes the whole affair in his memoir.
After learning the codename of this operation the Germans were naturally
keeping an eye for messages that referred to it.

In page 390 of
his memoirs he says about the files that Cicero copied from the ambassador’s
safe:

The contents so impressed me that at
first I devoted myself entirely to the study of the documents and almost forgot
to initiate those measures which must be carried out by the chief of a Secret
Service in such cases. However, I then ordered:

(a) the immediate presentation of the
reports to Hitler through Himmler.

(2) General Thiele (Chief of the
Wireless Security and Decoding section of the Wehrmacht Supreme Command) to
visit me at once to receive the material, which would enable him to start work
on deciphering the British diplomatic code (The four greatest decoding experts in
Germany, two professors of mathematics among them, worked on this material for
weeks until finally they were able to 'crack' a part of the code. It was a
tremendous achievement. Especially revealing were a number of handwritten notes
on the margins of the documents, technical data on code messages from London to
Ankara. Such things were of the greatest value to our experts.)

In page 393
he says:

In the meantime, by using the
documents we had been able to decipher part of the British diplomatic code. One
of the first important pieces of information we found in 'Cicero's' material
was that the planned invasion of France was to carry the code name Operation
'Overlord'. After the first appearance of these words in the document, I
immediately conferred with General Thiele. He at once started operations that
would enable us to determine where and when the code word 'Overlord' appeared
in the enemy's short-wave communications.

However his
postwar interrogation by the Allies, summarized in ‘Hitler's Last Chief of Foreign Intelligence: Allied Interrogations of
Walter Schellenberg’, p251 says:

Schellenberg maintains that he has
never seen deciphered British messages. He has learnt that the last successful
deciphering was that of British messages which went by W/T from Cairo to
London. After that a coding machine was introduced in Cairo which abruptly prevented
all further deciphering. General Thiele had continuously asked Schellenberg to
provide him with an English code machine or an English diplomatic or military
attache code still in use, but Schellenberg never succeeded in getting these.

Sunday, September 23, 2012

The Luftwaffe was one of the most interesting aspects of the
German war machine. Built from the ground up in the 1930’s it dominated the
skies over Europe in the first half of the war. Even in the latter part, when
it was grossly outnumbered by the Allies, it continued to fight on till the
last day of the war.

In the East the Luftwaffe played a vital role by
establishing air superiority, supporting the ground troops at the front,
bombing important targets deep behind enemy lines and keeping the enemy under
constant observation with its recon planes.

Unfortunately the full effects of the Luftwaffe’s efforts in
the East are not usually mentioned in most books.

Stopped at Stalingrad closes this gap by covering, in great
detail, the operations of the Luftwaffe in the summer campaign of 1942. The
author Joel Hayward is an expert on
Luftwaffe history and operations.

The first chapters cover the German conquest of the Crimea
in the summer of ’42 and show the great contribution made by the
Luftwaffe.Using airfields in the Crimea
aircraft could operate throughout the day on one fuel load and only landed to
reequip with bombs. Thanks to massive air support the Soviet forces in the
Kerch peninsula were defeated and Sevastopol leveled.

In May ’42 a surprise Soviet attack in the Ukraine using
their armored forces was soundly defeated thanks to swift Luftwaffe intervention.

The rest of the book deals with the German attack on the
Caucasus and details the countless missions that the Luftwaffe had to perform
every day.

When the Soviets counterattacked at Staligrad and the 6th
Army was surrounded, it was up to the Airforce to provide supplies. Hayward is
one of the few authors who cover the Stalingrad supply missions in detail.

Finally the book ends with the German counterattack in the
Ukraine in early 1943. The ground troops again received outstanding support
from their Airforce.

In all these operations the Luftwaffe played a vital role thanks
to its ability to generate a very large number of sorties from forward
airfields. Especially the ground attack units under General Wolfram von Richthofen acted as flying
artillery.

The book was a best seller for a reason. It is highly
recommended for anyone interested in the Luftwaffe and/or the Eastern Front.

Wednesday, September 19, 2012

In war efficient
and secure means of communication are vital for any undertaking. Without the
ability to communicate quickly with his underlying units a general will lose
control of a battle. Without the ability to control faraway units a military
command will see its forces attacked and destroyed piecemeal.

WWII historians
tend to focus too much on tanks and aircraft while at the same time neglecting the
huge effort made by the warring nations to build up modern communication networks.

During the
war the US Signal Corps built up a modern worldwide communications network for
US military and diplomatic authorities. This network was called ACAN (Army
Command and Administrative Network).

For the rapid
transmission of messages several types of equipment were used. Initially hand
Morse and Boehme (rapid Morse) equipment, then radiotype and finally the modern
radio-teletype (enciphered).

It was thanks
to these networks that the Allied commanders could efficiently command their
forces all over the globe.

German
interception of ACAN networks

These
networks were monitored by the German signal intelligence agencies and both
plaintext and cipher traffic was intercepted.

Due to the
very large number of messages passing on these networks some important
information was always available in plaintext transmissions. In addition some
of the hand codes used could be ‘broken’.

It also seems
that the Germans repeated their ‘Russian Fish ‘success by building a special
device that automatically intercepted and printed the teleprinter traffic.

There are few
details on this affair but I’ve tried to collate all the available information.

From postwar
interrogations it seems that at least 4 agencies intercepted and evaluated this
traffic.

1). The Army
Ordnance, Development and Testing Group, Signal Branch Group IV C-Wa Pruef 7/IV C at an experimental
station in Staats.

2). The
Signal intelligence Agency of the Supreme Command of the Armed Forces - OKW/Chi.

4). The Army
Signal Intelligence agency - OKH/GdNA from
bases in Norway and Euskirchen, Germany.

Wa Pruef
7/IV effort:

The Wa Pruef
7/IV C department has been mentioned before in connection with the ‘Russian
Fish’ equipment. It was headed by Bau Rat Kierkhoff and according to a
postwar interrogation there were about 5-6 engineers, 7-8 other men and 60 odd
Nachrichtenhelferinnen (women helpers).

Report FMS
P-038 ‘German Radio Intelligence’ says that the Staats station intercepted
Russian, British, American and French radio-teletype systems.

This traffic
was passed on to OKW/Chi and OKH/GdNA for analysis and evaluation.

OKW/Chi
effort:

Wilhelm
Flicke a member of OKW/Chi mentions in his book ‘War secrets in the Ether’ the
interception of US overseas traffic.

In pages
295-6 he says:

Of the "big fry" the USA
provided its enemies most amply with information. Among other things a special
radio network had been set up in 1942 which covered the entire globe. This was
the "WVNA-net" (named from the call-sign of the station in Karachi,
India, which was the first one heard.) Most of the exchange of messages could
be read currently; it afforded information on American military measures in the
Far, Middle, and Near East and in Africa. The following survey shows the extent
of the network in November 1942:

Flicke is
obviously describing ACAN. This is confirmed by the ‘Signal Corps-The Test’
which also mentions the same stations, for example: ‘After the Signal Corps' first large transmitter in India, at Karachi,
had begun operation in April 1942, satellite stations rapidly sprang up.’
and ‘The direct WAR to Cairo (WVNV)
circuit, after barely two months of service, was discontinued on Christmas Eve
1942 in favor of relay of the Cairo traffic by way of Asmara (WVNT).’

Unfortunately
he doesn’t expand on the kinds of traffic being passed on these links or the
codesystems used. However we know that OKW/Chi could decode several US
diplomatic codes during the war.

Luftwaffe
Chi Stelle effort:

The Luftwaffe
Signal Intelligence agency‘s LN Abt 350Referat
Bin Asnieres, Paris intercepted USAAF
and Naval AF traffic both Morse and radio-teletype. This section reached its
peak in terms of importance in 1942-3. Then in 1943 the part that dealt with
USAAF ferry traffic was split up and sent to Munich-Oberhaching.

The section
of Referat B which was moved to Munich-Oberhaching in 1943 was named Referat B5.
There was a large intercept station monitoring USAAF ferry traffic close by.

‘European Axis Signal Intelligence in World War II’ vol5 gives more details on the
operations of Ref B5:

‘The new Section evaluated all traffic and
had the following responsibilities: a) The monitoring of the United States
proper, which although it only touched the surface, still furnished an insight
into the principal networks of the Army and Naval Air Forces, into training
activity, air transport, defense zones, and the activation of new combat
aviation units. b) The monitoring of the Atlantic ferry service. The Middle and
Central Atlantic routes were monitored by the W/T platoon in Oberhaching and by
Luftwaffe Signals Intelligence Service outstations in Spain, which operated under
the cover name of ‘Purchasing Agencies’; the North Atlantic route was monitored
by the 16th Co., LNR 3 and reports furnished to the Section. c) The monitoring
of the American Air Transport Command by the platoon in Oberhaching. d) The
monitoring of the RAF Transport Command and of both American and RAF troop
carrier commands. The greater part of this interception was also done in
Oberhaching.’

US
radio-teletype was also intercepted by a LN Abt 350unit in Berlin-Schoenfeld. The types of traffic intercepted were
FF5 and FF6, which refer to 5-unit T/P and Radiotype respectively. A German
report from November 1944 says that the Schoenfeld unit had 14 Rhombus
installations, an intercept hut with 12 intercept rooms and total strength of
52 men. Intercept equipment was provided by Wa Pruef 7.

In postwar
interrogations German personnel mentioned that USAAF T/P ferry traffic was read
during the war.

Friedrich,
head of Luftwaffe signals intelligence, stated in TICOM I-13:

‘KAMERUN’
(CHI Stelle Ob.d.L., Referat B) when located at PARIS-ASNIERES had intercepted
and broken U.S. non-morse teleprinter traffic between WASHINGTON and EUROPE.
This success was maintained throughout owing to the lamentable insecurity of
the operators. The Germans had therefore always known all details of ferry
flights, strength of the U.S. Air Force in Europe and a good deal about
training and replacements.’ and ‘Yes.
It was wireless teleprinter traffic from Washington State Department. No. Not
to Europe: to overseas W/T stations. It was a 'Zutraegerverkehr, (traffic
passing on signals in bulk). There was an immense volume of traffic. Breaking
ceased when a new machine or a new 'Tastschritt’ (keying tempo ?) was
introduced. Yes, there was a secrecy device, but it could be broken by the most
primitive methods; there were 10 GAF WAAF only to cope with it. The traffic did
not carry signals of any tactical importance. No, this was not before, but
after, the Americans entered the war. But breaking ceased a long time ago. Yes,
a special receiver had to be built. 'As far as I can remember, but I don't want
to be bound to the statement, the receiver was built for me by a Feldwebel'.
The alphabet was a kind of morse substitution. What should have been A came out
as, say, M. No, it was not this impulse business.’

The follow-up
report I-29 says:

1. Reference was made to Friedrich's
previous statements about the breaking of an American
"Funkfernschreib" system. See Ticom/I-13. ((Note: as will be seen,
the whole difficulty about this claim arose from his use of the quoted term
'teleprinter' when he meant in fact 'undulator', and from a misunderstanding
about the terminals of the traffic)). He was asked when the breaking began, and
stated that it was shortly after the entry of the U.S. into the war. It was
traffic between the War Dept and the regional traffic collecting centers, he
could not recall the locations of these centers, but they were all within the
United States. They were specifically not in Iceland or Greenland. The
transmission was described as teleprinter ((wrong)) short-wave. It was
encinhered but was easy to break. It was Morse traffic, not impulse. It was
recorded by teleprinter ((i.e. undulator)) on a printed strip as dots and
dashes [but see below]. This was enciphered morse, not clear text. He had a
special receiver built by a Feldwebel for taking it. it was multi-channel [but
see below]; he does not know what kind. The contents of the traffic were: training
instructions, development of airfields and details of selective service
processes.

2. He was asked whether this was the
traffic from which he had said they got details of ferry flights; it was,
particularly details of the preparations for flights and of the routes. The
traffic dealt with the bringing of aircraft to assembly points, then their
transfer to ferrying ports, and finally with their flights to North Africa,
Gibraltar, and later straight to Great Britain.

3. Was the morse just scrambled for
transmission, or was there a cipher underneath? Didn't know. After unscrambling
the channels, did you have clear text, or was there a further encipherment to
solve? Reply: there is a misunderstanding. The multichannel scrambling method
to which we referred is the method used by the Americans later on, and which
the GAF failed to break, because of lack of apparatus. The traffic in question
was originally just Plain morse. The new "Tastschritt" affected only
the German interception, not us. Asked to define Tastschritt, he said it did
not mean "keying speed", but the synchronizing of the intercept
equipment with the recorder. He was asked to explain the inconsistency of his
referring to the traffic both as teleprinter and as morse. He then drew a
picture of an undulator tape, single-channel, and marked off the undulation
into successive Morse letters. He said this was what he meant by
Funkfernschreib. Each letter was different from the corresponding clear text
letter. He could not remember any of the indicators. The preamble gave ample
routing instructions, and enabled them to couple the names of towns with
call-signs and personal names. The text itself was very stereotyped, especially
the addresses. He did not recall whether cleartext was mixed with cipher. He
was asked whether they considered it a high-grade system, and replied that they
did not, but that there was so much material in it, that if they could have
allotted it sufficient time and personnel, they would have got a good deal of
valuable information from it. It dealt in addition with the production and
development of aircraft. However they had other things to do, and other sources
of information, so this materiel was not fully exploited. We asked what these
other sources were. He said all of the ferry-flight air-ground traffic was read
by III/LN Rgt 3 also in Sicily and gave expected times of arrival and
departure, weather, and strength of groups of planes being ferried.

4. It was asked whether the morse
signs on the undulator were converted into letters or figures. They were
letters. When did the breaking cease? He found this very difficult to recall.
It was long before the invasion of France. We asked if it was before the
invasion of North Africa. He said it was at just about that time, but he could
not remember whether it was shortly before or shortly after. Asked what the
change was, he could not recall. Was it to teleprinter or to multichannel. He
thought it was not teleprinter as he had never had a receiver built which would
take that. Question: Then they were still able to intercept it? Yes. In what
form? Doesn't know. Still on tape? He thinks so. Who else intercepted this type
of traffic-what other units? OKW did. In Husum? No. Dr. Pickering then said
that FNAST 3 (Euskirchen) personnel had told a somewhat similar story (to be
published). He replied that it was very likely that this was the same traffic,
as KAMERON (unit intercepting for GAF) corresponded with Euskirchen on systems
which they both worked on. He agreed with the Euskirchen statement that it was
a simple substitution. ((Comment: Not too much credit should be placed in this
statement, as he was just adopting a suggestion)).

Voegele,
chief cryptanalyst of the Luftwaffe in the West said in I-112: ‘From April to October, 1944, clear radio T/P
messages were intercepted regarding a/c movements between America and North
Africa. similar messages in cypher with 6 letter indicators were also
intercepted but these could not be read.’

The Army Airways
Communication Service

During the
war special support was given to the AACS which belonged to the Airforce.
According to the ‘Signal Corps -The Outcome’: ‘AACS differed from ACAN in that it was strictly an AAF organization,
manned and operated by the airmen, though Signal Corps men supplied the
equipment, engineered and set up the installations, and in the early days of
the war often operated the communications lines too, until the AAF could do so
with AACS men, who very often merely transferred over from the Signal Corps.’

It seems
reasonable to assume that the networks exploited by the Luftwaffe belonged to
the AACS. That would explain the traffic dealing with aircraft movements.

Apart from
Morse, the AACS was provided with single-channel radio-teletype with automatic
enciphering in order to deal with the traffic loads it transmitted daily. The
official history ‘Signal Corps -The Outcome’ says: ‘It was the South Atlantic route to Africa and Europe that first got the
single-channel RTTY net, along the string of Caribbean islands to the bulge of
Brazil, across the South Atlantic via Ascension Island, reaching Dakar by
mid-1943.’

OKH/GdNA
effort:

The German
Army’s Signal Intelligence agency - OKH/GdNA had a special group that
intercepted high level enemy radio-teletype traffic. This was Group VI split into
Referat 1 operating in the East and Referat 2 in the West.

The Ref 1
unit intercepted Soviet multichannel radio-teletype, both plaintext and
enciphered, with special equipment. Members of this unit were captured in May
’45 by the Allies and taken to the UK with their equipment.

The Ref 2
unit was based in Euskirchen, Germany. This was the base of Feste 3 (Feste
Nachrichten Aufklärungsstelle/Stationary Intercept Company).

According to
report ‘CSDIC 1717’ Group VI Ref 2 was headed by inspector Heller and was divided
in Ref 2A which evaluated the British and American T/P and automatic Morse traffic
and Ref 2B that intercepted it. Roeder, head of Group VI at the end of the war,
stated in TICOM I-99 that the Western unit had about 15 soldiers and 30 helpers
plus 10 receiving apparatus.

US traffic
was also picked up by Feste 9 in Norway. In report CSDIC/CMF/Y 40 it is stated
that Feste 9 intercepted US traffic both manual and automatic from domestic
bases and stations abroad (Atlantic area, Caribbean, Middle East, India).

Some of this
traffic was enciphered with systems that the Germans had solved. These were the
War Department Telegraph Code, the Division Field Code and the M-94 strip
cipher.

There was a
special device ‘funkfernschreibverkehr’
used by funkmeister Rudolph ‘anexpert on WT TP intercept’. This is a reference to the interception of Baudot
radio-teletype and Radiotype.

IBM Radiotype,
APO numbers and promotion letters

In order to
build a modern communications network the Signal Corps wanted radio-teletype
units with automatic enciphering and deciphering capability. In 1942 they did
not have such equipment so they had to settle for a similar machine called
radiotype.

‘The first working model of the Radiotype was
fabricated in 1931 in the laboratory of Radio Industries Corporation under the
direction of Walter S. Lemmon, who was then the company's president, Clyde J.
Fitch, an engineer, and A. M. Nicolson.

……………………………………………………………………………………………………..

In 1935 Admiral Richard E. Byrd
successfully sent a test Radiotype message 11,000 miles from Antarctica to an
IBM receiving station in Ridgewood, New Jersey. Six years later, IBM lent
Radiotype machines to the U.S. Signal Corps for tests between Washington, D.C.,
and Dayton, Ohio. These tests were conducted by Albert Holt, an IBM field
engineer in the Radiotype Division. With the U.S. entry into World War II, the
Signal Corps ordered quantities of the Radiotype machines to equip its stations
in San Francisco, Honolulu, Panama, Puerto Rico and elsewhere.’

The ‘Signal
Corps-The Test’ says: ‘The International
Business Machines Corporation had worked out an imperfect solution involving
equipment that the firm called radiotype, using, unfortunately, not the
standard five-unit teletypewriter code but a special six-unit code. Like a
narrow gauge railroad adjoining a standard line, this special code necessitated
much hand labor at conversion points where standard teletypewriter texts had to
be shifted onto radiotype circuits, and vice versa. Moreover, the standard
automatic cipher machines could not function with the six-unit system.
Notwithstanding these inconveniences, the Signal Corps early in the war began making
use of radiotype, leased from IBM. It was another step in the right direction, toward
automatic, high-speed, heavy-duty communications for the Army.’

According to
the same source the use of radiotype was extensive during the war: ‘Radiotype would continue to be used
considerably. Not till September 1943 would the Signal Corps stop its procurement
in favor of radioteletype and not until May 1945 would the Army take its last
radiotype out of service (on the WAR-Accra circuit). Then the triumph of
radioteletype would be complete.’

The Germans
were able to exploit the internal US traffic from 1941 onwards. The Army
intercepted it from Euskirchen and from Norway.

By monitoring
the internal US radio traffic the Germans could follow the activation and
movement of units through their APO (Army Post Office) number. It was
understood that divisions sent to West coast harbors went to the Pacific
theatre while those sent to East coast harbors went to the Atlantic theatre. Valuable intelligence was
also gained from officer’s promotion letters.

Initially
this traffic was Morse but the introduction of radiotype forced the Germans to
build specialized intercept equipment.

FMS P-038
says: ‘In the spring of 1942 a new
transmitting technique was introduced in American long-distance communication
(both domestic and foreign) that dried up this excellent source of German
intelligence. The Euskirchen station, which was charged with cryptanalysis of
this traffic, solved the riddle within one week, however, by means of tape
recordings and systematic analysis. It was finally discovered that the process
used was a rapid system of wireless telegraphy which differed from the usual
method by the number of current impulses. This was the ‘Radiotype’ method. A
tremendous number of military and business messages were soon intercepted.
After a short while the receiving operators were able to ‘read’ the message
tapes as fast as Morse code. Fortunately, after a pause of one week, military
messages in clear text became more frequent for a time. This mistake was not
discovered by the Americans until later, at which time they began to encipher
these mechanically transmitted messages. Since it was no longer possible to
solve them, work on these messages was discontinued.’

This may
refer to the introduction of the SIGCUM cipher machine in early ’43 and its
immediate withdrawal due to a security problem. Or it could refer to operator
mistakes described in ‘The Signal Corps-The Outcome’: ‘The on-line features had a serious security disadvantage, however, in
that the operator on the transmitting end sometimes forgot-when passing from
unclassified traffic sent in the clear to classified-to flip the switch that
would connect the on-line crypto equipment.’

The Germans
did not always get good intelligence from ACAN. David Kahn says that the Allies
managed to deceive them regarding the divisions sent to Britain in 1944 by
sending fake radio messages. However he doesn’t provide more details.

On the other
hand a member of Feste 3 named Wingender states in TICOM I-76 that even
‘fictitious stations and traffic’ were recognized thanks to violations of radio
discipline and cipher security.

Radio-teletype
and SIGCUM

Radiotype was
only a temporary solution and from 1943 it was being replaced by regular 5-unit
(Baudot) radio-teletype.

In order to
protect this traffic the Americans developed a cipher attachment that
automatically enciphered and deciphered the traffic. This device was called Converter M-228 or SIGCUM and
was introduced in January 1943.

Its initial
debut was not successful as a flaw in its security was found and a decision was
made to delay its entry into service for several months.

It was
finally put into use in April 1943. From then on ACAN teleprinter networks
would be secure from eavesdroppers.

Unanswered
questions

Although the
information we have is enough to form a rough understanding of German operations
there are many missing elements.

We lack
details on the history and performance of the German agencies regarding their
interception of ACAN.

What kind of
intercept equipment did they use? How much traffic did they intercept? How much
of it could they decode?

Did they
attack the SIGCUM traffic cryptanalytically or simply use it for traffic
analysis?

Another
important question is whether the Radiotype system was used with a cipher
attachment of some sort. Was that the simple substitution that the Germans talked
about? We do know that standard cipher attachments could not be used on it
because of its 6-unit operation.

‘Building IBM: Shaping an Industry and Its
Technology’says in page 348: ‘The use of Radiotype coupled directly to encryption and decryption
equipment, is reported by J. C. McPherson. 8 August 1991: discussion with E. W.
Pugh.’

Let’s hope
that some of these questions will be answered in the future.

Sunday, September 16, 2012

The Luftwaffe
was supposed to be a ‘tactical’ airforce that failed to invest resources in
‘strategic’ aircraft that could have won the war.

I’ve already
criticized that opinion here.
Throughout the 1930’s and 40’s the Luftwaffe spent the majority of its
resources on the bomber arm. The best pilots were selected for the bombers.

Compared to
the Allied airforces the Germans had superiority in technology and numbers at
the start of the war. No other airforce had radio beam systems (like Knickebein and X-Gerat) for guiding bombers.

'The foregoing account of the Battle of
Britain throws light on the main factors which contributed to the defeat of the
Luftwaffe. It is as well, however, to enumerate those factors and to examine to
what extent and to what degree each was responsible. The main factors may be
summarized as follows:

(a) A fundamental failure in German
air strategy and policy, which concentrated on the doctrine of attack, and thereby led to a
disproportionate weakness of the fighter
arm as opposed to the strength of the bomber
and dive bomber forces. The armament
of the German He 111, Do. 17 and Ju.88 bombers which, in conjunction with their
speed, had been relied upon in part to offset the deficiency of fighters,
proved inadequate and led to a wasteful use of the limited strength of the
fighter escort and to disastrous quarrels at a crucial point in the Battle.'

While it is
true that in the second half of the war the Anglo-Americans fielded large
4-engine bomber forces it needs to be remembered that the StrategicTM
RAF only started getting its new 4-engine models in late 1941 and up to mid
1943 the operational numbers were between 200-300 planes.So if the
Luftwaffe was a ‘tactical’ airforce then that can only be true for the period
1943-45. This is understandable since from 1941 the Germans were involved in a
life and death struggle in the East and had to spend huge resources on their
land forces. Under these circumstances the Luftwaffe could not get the
resources it needed nor could production facilities be allocated for aircraft
that would take years to build and field in numbers.

Think about
that next time someone says the Luftwaffe was a tactical airforce.

Wednesday, September 12, 2012

One of the
high level British cryptosystems exploited by the Germans in WWII was the Interdepartmental
Cypher. This was a 4-figure codebook enciphered with 5-figure subtractor
tables.

The ID Cypher
was used by the Foreign Office, Colonial, Dominions
and India offices and the Services. Also used by the Admiralty for Naval
Attaches, Consular Officers and Reporting Officers.

The
Germans captured the codebook from the British consulate in Bergen in May 1940
and subsequently ‘broke’ the encipherment. Although their success was mainly
based on cryptanalysis, they also received some enciphering tables from the
Japanese in 1941.

All
the German agencies (OKW/Chi, Forschungsamt, Pers Z plus the cryptanalytic
agencies of the German Army, Navy and Airforce) worked on the ID Cypher and
they exchanged results. During the period 1940-43 they were able to gain valuable
diplomatic and military intelligence by reading the messages.

The
Navy’s central
cryptanalytic department OKM/SKL IV/III (Oberkommando der
Marine/Seekriegsleitung IV/III) was able to decode the British Admiralty’s weekly
intelligence summaries sent to naval attaches. In addition messages from the
Freetown Area were decoded and provided intelligence on the movement of heavy ships
and convoys. Traffic between the Admiralty and Consular
Officers and Reporting Officers gave information on convoys and independently
routed ships in the Atlantic. From ADM 1/27186 ‘Review of
security of naval codes and cyphers 1939-1945’,
p75-76

Diplomatic
messages were solved by OKW/Chi, the Forschungsamt
and Pers Z. Interesting information was received regarding negotiations between
Britain and Turkey.

The
German efforts were assisted by poor British cipher practices. A security
investigation in 1942 showed that the tables were overloaded, leading to heavy
‘depths’ and the indicators were not selected correctly.

The
German success finally ended on 15 June 1943 when the codebook was changed.

Numerical
strength goes up dramatically during the period 1941-43. From 385 fighters and
bombers in May ’41, to 1.202 in May ’42, to 2.926 in May ’43 (including NWAAF).

In terms of
quality the picture is not as clear as regards quantity. Even though the Brits
have the excellent Spitfire fighter, in the Med they use the outdated Hurricane
and the US P-40. Both these planes are inferior to the Bf-109. The Spitfire is
finally used from mid 1942 but is only available in large numbers in late ’42.

The bomber
force also suffers from mediocre quality. Initially it is made up of the outdated
Blenheim and Wellington types. In 1942-43 the US types Boston, Maurauder,
Baltimore, Maryland and Hudson are also used.

Standardization
does not seem to be an issue with the RAF. In 1941 there are 2 fighter and 4
bomber types in use. In 1942 there are 6 fighter and 9 bomber types. Finally in
1943 there are 5 fighter and 8 bomber types.

Lend Lease
plays a vital role in N.Africa, as the American P-40 fighter and the Boston,
Maurauder, Baltimore, Maryland and Hudson bombers make up a large part of RAF
strength in the theatre (roughly a third of ME Command in 1941-42).

Comparison
with Axis strength:

Unfortunately
I don’t have similar data for the Italian AF but Luftwaffe strength for
Luftflotte 2 and Sud Ost has been posted here.

The RAF had a
significant numerical advantage over the German AF, however that does not mean
that the Germans were always outnumbered.

Against Malta
the Luftwaffe could concentrate a large force of fighters and bombers operating
from Sicily. In the first half of 1942 they had between 300-400 combat planes
versus less than half as many British planes.

On the other
hand in North Africa it was the Brits that had crushing superiority. The
strength of Fliegerführer Afrika
fluctuated between 200-300 planes versus up to 6 times as many in Middle East
Command.

The Germans also
faced serious supply problems that forced them to rely mainly on the Bf-109 and
Ju-87. Bombers like the Ju-88 could not be permanently based in N.Africa but
operated from Italy and Greece and were resupplied in N.African airports. The
RAF on the other hand had the benefit of a large number of twin-engined bombers
operating from N.African bases.